[nvptx] Add nvptx_mach_vector_length, nvptx_mach_max_workers

The vector length and maximum number of workers are known compile-time.  Make
these easily available during code generation via new functions.

2019-01-03  Tom de Vries  <tdevries@suse.de>

	* config/nvptx/nvptx.c (MACH_VECTOR_LENGTH, MACH_MAX_WORKERS): Define.
	(init_axis_dim, nvptx_mach_max_workers, nvptx_mach_vector_length): New
	function.
	* config/nvptx/nvptx.h (struct machine_function): Add axis_dims.

From-SVN: r267558

gcc/ChangeLog

 2019-01-03  Tom de Vries  <tdevries@suse.de>
 
+	* config/nvptx/nvptx.c (MACH_VECTOR_LENGTH, MACH_MAX_WORKERS): Define.
+	(init_axis_dim, nvptx_mach_max_workers, nvptx_mach_vector_length): New
+	function.
+	* config/nvptx/nvptx.h (struct machine_function): Add axis_dims.
+
+2019-01-03  Tom de Vries  <tdevries@suse.de>
+
 	* config/nvptx/nvptx.c (struct offload_attrs): New.
 	(populate_offload_attrs): New function.  Factor mask extraction out of
 	nvptx_reorg.  Add extraction of dimensions.

gcc/config/nvptx/nvptx.c

@@ -2883,6 +2883,47 @@ struct offload_attrs
   int vector_length;
 };
 
+/* Define entries for cfun->machine->axis_dim.  */
+
+#define MACH_VECTOR_LENGTH 0
+#define MACH_MAX_WORKERS 1
+
+static void populate_offload_attrs (offload_attrs *oa);
+
+static void
+init_axis_dim (void)
+{
+  offload_attrs oa;
+  int max_workers;
+
+  populate_offload_attrs (&oa);
+
+  if (oa.num_workers == 0)
+    max_workers = PTX_CTA_SIZE / oa.vector_length;
+  else
+    max_workers = oa.num_workers;
+
+  cfun->machine->axis_dim[MACH_VECTOR_LENGTH] = oa.vector_length;
+  cfun->machine->axis_dim[MACH_MAX_WORKERS] = max_workers;
+  cfun->machine->axis_dim_init_p = true;
+}
+
+static int ATTRIBUTE_UNUSED
+nvptx_mach_max_workers ()
+{
+  if (!cfun->machine->axis_dim_init_p)
+    init_axis_dim ();
+  return cfun->machine->axis_dim[MACH_MAX_WORKERS];
+}
+
+static int ATTRIBUTE_UNUSED
+nvptx_mach_vector_length ()
+{
+  if (!cfun->machine->axis_dim_init_p)
+    init_axis_dim ();
+  return cfun->machine->axis_dim[MACH_VECTOR_LENGTH];
+}
+
 /* Loop structure of the function.  The entire function is described as
    a NULL loop.  */
 

gcc/config/nvptx/nvptx.h

@@ -218,6 +218,9 @@ struct GTY(()) machine_function
   int return_mode; /* Return mode of current fn.
 		      (machine_mode not defined yet.) */
   rtx axis_predicate[2]; /* Neutering predicates.  */
+  int axis_dim[2]; /* Maximum number of threads on each axis, dim[0] is
+		      vector_length, dim[1] is num_workers.  */
+  bool axis_dim_init_p;
   rtx unisimt_master; /* 'Master lane index' for -muniform-simt.  */
   rtx unisimt_predicate; /* Predicate for -muniform-simt.  */
   rtx unisimt_location; /* Mask location for -muniform-simt.  */